Effect of Ni on vacancy concentrations and hardness in FeAl alloys

Journal Article · Wed Jul 01 04:00:00 EDT 1998 · Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science

DOI:https://doi.org/10.1007/s11661-998-0015-3· OSTI ID:634564

Pike, L M; Chang, Y A ^[1]; Liu, C T ^[2]

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1. Univ. of Wisconsin, Madison, WI (United States). Dept. of Materials Science and Engineering
2. Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

The effects of nickel additions to iron aluminides are investigated with respect to vacancy concentrations and solid-solution hardening. Lattice parameters, densities, vacancy concentrations, and hardnesses were measured for FeAl alloys (40, 45, 48, 50, and 51 at. pct Al) with up to 12 at. pct Ni additions, as quenched at both 700 C and 1000 C. It is found that Ni does not prevent the elimination of thermal vacancies, as has been suggested in previous studies. However, the equilibrium vacancy concentrations are affected by the Ni additions. No clear evidence of solid-solution hardening by the Ni additions themselves was found. Instead, it appears that the role of Ni in hardening FeAl is through the effect the Ni has on the vacancy concentration. It was found that the hardness of most of the Ni-containing FeAl alloys could be directly correlated to the square root of the vacancy concentration.

• Sponsoring Organization: USDOE
• OSTI ID: 634564
• Journal Information: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 7 Vol. 29; ISSN 1073-5623; ISSN MMTAEB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
CRYSTAL STRUCTURE
HARDNESS
HEAT TREATMENTS
INTERMETALLIC COMPOUNDS
IRON ALLOYS
LATTICE PARAMETERS
NICKEL ALLOYS
VACANCIES